Wash and soak the rice and dal separately for 3 hours.
Drain the water from the urad dal and grind this into a smooth paste.
Do not add much water while grinding.
Sprinkle water and grind into a smooth paste as how we do for urad dal vadai.
Grind the rice into a rava consistency.
Transfer both the batter into a bowl.
If making the vadais later, keep the batter inside the fridge.
Just before making, add the finely chopped small onions, green chili, coconut bits and salt.
Combine well.
Ensure the batter is not too tight.
If it is thick add 1-2 tbsp of water and mix it well.
Heat oil for deep frying.
When it is hot, take small portion of the batter and drop it in the oil.
Fry in medium flame.
Flip on both sides and fry till golden brown.
Take out from the oil and drain in the kitchen towel.
Repeat for the rest.
Kurunai vadai is ready.
Serve with hot tea or coffee.